Circuit interrupter



responsivetoapredetermined fliedconstructlonoi'a eraltype Patented May 1943 l CIRCUIT INTERRUPTEB Herbert L. Rawlins, Wilkinsbur Wallace, North Braddock, Westinghouse Electric mi Penn and Jannes M. Pa., lllllol's t0 Manufacturing Com- Il'iast Pittsburgh, Pa., a corporation of Application-lilly 19, 1940, Serial No. 346,350

Our invention relates generally to electric circuit interrupting means, and more to a novel circuit breaker construction which is capable of automatically reclosing the circuit in response to a circuit interrupting operation.

Our-invehtion relates,

of circuit breaker having separable contacts normally biased closed, with current responsive means for separating to draw an arc pressure generated by said arc is utilized to iuilyopenthecontacts. frime delaymeansis provided to oppose the action of said biasing meausinclosingthebreakercontactaandtobe number of closely said contacts s'umciently This general type of breaker is disclosed and claimed in'the copending application of J. M. Wallace for Circuit interrupter, Serial No. 345,051, filed July 12, 1940, and to the Westinghouse Electric I: Manufacturing Com- Dany, the of this application.

Our invention, while embodying some of the general features Voi' said is sbeciilcally directed to animproved andsimplicircuit breaker oi this gen- One object of our invention is. to provide a novel circuit Ybreaker construction of the type described, which is oi' a relatively simple and compact construction.

Another object of our invention is to provide in a circuit inten'upter havingseparable contacts located in a substantially closed arc chamber, novel means tor ilushing said chamber of arc gases and introducing therein-a fresh supply oi.'

,an arcmedium in response to each interrupting operation thereof. 4

Another object of our invention is to provide in a circuit breaker which automatically recloses the contacts thereof in response to a circuit interrupting operation, novel means i'or delaying the reclosure of said contacts a predetermined time after the preceding interrupting operation. Another object ci.' our invention is to provide novel lockout means for an automatically reclosing circuit breaker, which means is responsive to a predetermined number oi' closely succeasive reclosures of said breaker to lock the breaker contacts in lan open pomtion.

Another object of our invention is to provide in an automatically rec circuit breaker, novel combined time delay means for the reclosing operation, and lockout means i'or locking the breaker contacts open in response to aprede.

in general, to the type and having meanswhereby thel reclosures to lock the contacts open.

` 49Claims. (Cl. 200-116) termined number of successive reclosures thereof.

Another object of our invention is to provide novel current responsive tripping means for a. circuit breaker.

Another object of our invention is to provide in a circuit breaker of the type described, current responsive tripping means for a, circuit breaker which is operable in response to the passage therethrough of currents above a predetermined value to positively move at least one oi.' the breaker interrupting contacts out of engagement with the. other of said breaker contacts.

A further object oi' our invention is to provide `a circuit breaker having separable contacts immersed in an arc-extinguishing liquid, with novel indicating means for indicating the quantity of liquid in thev breaker.

A'still further object -of our invention is to provide a novel arrangement oi' parts of a circuit breaker ot the type described, and wherein the separable contacts thereof are immersed in an arc-extinguishing liquid.

'Ihese andA other'obiects of our invention will become more apparent upon consideration oi the following detailed description of a preferred embodiment thereof, taken in connection with the attached drawings. in which:

Figure 1 is a substantially central longitudinal cross-sectional view through` a circuit breaker embOdylng our invention;

-right angles to the plane of Fig. l;

Fig. 3 is aview like Fig. 1 but showing the operating parts of the circuit breaker in an open position;

Fig. 4V is a top plan view of the circuit breaker shown in Figs. 1, 2 and 3 with the outer cover removed; and

Fig. 5 is a side elevational view ci the upper end of the circuit breaker sh'own in Figs. 1 to 4, with the outer cover 1n section. Referring to the drawings, the circuit breaker illustrated therein .is shown in an insulating tubular casing 2 which may be of any desired insulating material, such for example, as porcelain, glass, or the like. The 2, as shown in Fig. 1, has a closed bottom end portion and an open top. vThe open top is provided with an upper terminal cover assembly I, and the closed bottom of the casing is provided with a lower terminal assembly 6.- An intermediate portion on the casing has a substantially cylindrical wall portion I upon which is mounted as being contained supporting brackets I2, as by bolts I4. The outer end of each bracket I2 may be turned laterally as at I'I, and apertured as at I6, for the reception of a bolt for securing the brackets in position on a pole or other supporting structure.

The lower terminal assembly 6 is mounted at the closed bottom portion of the insulating casing 2 by means of a bolt I8 extending through an aperture I9 in the closed end of the casing 2, and the bolt is provided with an enlarged disc-like head portion 26 positioned within the casingZ,

with packing material 22 interposed between the head 26 and the adjacent inner surface of the closed end of insulating casing 2. The packing material 22 may be of any desired packing inaterial, preferably one resistant to oil, such for example, as cork, ber, or synthetic rubber. Bolt i8 has a bore I5 therethrough, the outer end of which is closed by a threaded plug 2i for the purpose of draining casing 2 when desired. The bolt i8 is secured in position by a nut 24 drawn up on the bolt against a washer 26 positioned between the nut 24 and the outer wall of the closed end of the casing 2. A terminal strap 28 may be also secured to the bolt i6 as by means of a second nut 36, for supporting terminal sockets 29 having one side thereof secured in notches in .a downwardly extending portion of strap 28, with clamping screws 3l threadedly engaged in apertures in the socket walls for securing a conductor therein.

The upper terminal assembly 4 is in the form of a cover for the open end of the casing'z, which not only acts as a cap or cover for the casing, but, as will be hereinafter more fully explained, acts as a support for the interrupter and its operating mechanism when in operative position within the casing 2.' Referring to Figs. 1 and 2, it will be.

noted that the cover 32 is provided with a transversely extending relatively narrow hollow portion for the reception of certain parts of the cirfcuit breaker operating mechanism, and the top wall of which is provided with an aperture for the reception of a screw threaded filler plug 34, so that the supply of arc-extinguishing uid within the casing 2 may be renewed when necessary. The cover 32 includes a peripheral ilange portion 36 adapted to seat on the upper end walls of casing 2, and this flange hasat its outer edge a downwardly turned lip portion38 for properly positioning the cover on the open end of the casing 2. Packing material 46 is interposed between the cover and the open end lof the casing similar to the packing material 22, and the cover 32 is secured to the casing 2 by means of a support 42 xedly Vmounted on the outside of the casing 2. The support 42 is in the form of an annulus which is substantially channel-shaped in cross-section, with the channel facing the outer surface of casing 2. The anular support 42 is secured to the casing by cast metal or the like 44, which is poured in .between the support 42 and the outer casing wall so as to enter within the channel of the support 42 and between corrugations 46 provided on Athe outer surface of the casing to securely anchor the support 42 thereto. We provide a plurality of laterally extending ears 52 and 50 on the support 42 and cover ange 36, respectively, which ears are apertured for the reception of bolts 48 for securing the cover to the supporting ange 42 and, therefore, to the insulating casing 2.

The insulating casing 2 may be of any desired shape and cross-section, preferably circular, as

shown, so that thehollow portion of the cover 32 described above extends substantially diametrically of the casing, and so that segmental portions of cover flange 36 extend inwardly over the open end of the casing as shown at 54 in Fig. 2. Secured to these segmental portions of the cover flange 36 are spaced supporting plates.56 having angularly bent ends insulatingly secured to the segments 54 of cover ange 36, by machine screws 5l, with interposed insulating washers 58, and insulating bushings 60. The insulating washers 58 and bushings i(il) may be of any desired insulating material such as ber, or a synthetic resin material. As shown, the supporting plates 56 extend substantially in parallel relation downwardly in the tubular insulating casing 2, and one function of these plates is to support a tubular interrupter housing 62. The interrupter housing 62, as shown, is substantially circular in cross-section, although it is obvious that any other desired cross-section may be employed ifv screw threaded, and one end is threaded into an Y end of a metallic tubular section 66 to form the housing 62. A lower end capl 68 is threadedlx'7 engaged with the lower end of the insulating tubular section 64, and an upper end cap'lil is threaded into the upper end of the metallic tubular section 66. plates 56 are secured to the tubular housing 62 by screws l2, engaging the upper end cap 10. The lower end cap vE58 is reduced in section to provide a shoulder against which the upper end of a coil compression contact spring 14 is seated, to be compressed against the enlarged head 20 of bolt I8 of the lower terminal assembly 6.

VSpring i4 may be of any desiredvresilient conducting material, such as a copper alloy.

A substantially central bore is provided through the lowe'.` end cap 68 which includes an upper threaded portion 16, an intermediate cylindrical portion 18 and an outer bore 80 of reduced area. A anged bushing 82 is threaded into the upper portion 'I6 of the bore through the lower end cap 68, and this bushing is preferably of material capable of withstanding arcing, such for example as a tungstenralloy.4 The anged bushing 82 is itself provided with a bore as shown. Slidably mounted in the cylindrical portion I8 of the lower end cap bore is a valve disc 84 resiliently urged into engagement over the lower end of the bore through the flanged bushing 82, by a coil compression spring 86 seated between the valve disc 84 and the shoulder provided at the lower end of the cylindrical bore portion 18. This valve arrangement acts as a pressure relief means for the tubular insulating member 64,.'and the strength of spring 86 is chosen so as to permit the valve disc to openv the passage through the lower end cap in responseto predetermined pressures in insulating with the interior of casing 2. The circular groove 88 is controlled by a substantially annular valve disc 92 which is freely movably mounted between the upper surface of end cap 68 and the adjacent end of insulating tube 64.

A hollow contact rod 36 is provided with a 1on- As shown, the supportinggitudinally extending central bore and with an arcing cap 99 threadedly engaged over the lower end thereof, so that in the closed pomtion of the contact, the cap 99 engages the flanged bushing 92, which forms a stationary contact. The arcing cap 99 of the movable contact rod is provided with an aperture `|99 to communicate the interior of insulating tube 94 with the interior oi' the hollow contact rod 99. The movable contact rod 99 extends through an aperture in a closure disc 94 for the upper end of insulating tube 94 in slidable relation therewith. As shown, the closure disc 94 is threadedly engaged in the metallic tube 99 to be tightly engaged with the upper end of insulating tube 64, and the aperture through the closure disc 94 is of. a size to closely llt arcing rod 99, so as to prevent leakage of pressure from insulating tube 94 at this point. Obviously, insulating tube 94, end cap 99 and closure disc 94 together form a substantially closed arc chamber 99. Adjacent the lower end of movable contact rod 96 the bore in said rod is enlarged to form a shoulder |92 therein, on which is seated a partition disc |94'maintained in po'- sition to close oif thebore through the contact rod by a coil compression spring |99, having the opposite ends thereof in engagement with the` disc |94 and with the arcing cap 99, respectively. Below the partition disc |94 in the movable contact rod 99 there are provided vent apertures |99, extending through the side walls of hollow contact rod 99 for a purpose to be described.

In the operation of the parts of our novel circuit breaker thus far described, it will be noted that we have provided a substantially closed arcing chamber 99. Thus when the movable con- Atact rod 99 is moved upwardly in response to currents in excess of a predetermined value in the circuit, an arc will be drawn between the arcing cap 99 on the contact rod and the flanged bushing 92. Inasmuch as the arcing chamber is disposed well below the level of arc-extinguishing liquid L maintained in the casing 2, it will be substantially filled with such liquid and the arc formed will produce gases'under pressure. due principally to decomposition of the arc-extinguishing iluid, and this pressure developed within .the arc chamber will move the movable contact rod 99 a further distance away from the stationary' contact and out of the arc Vchamber in a piston-like manner.

The pressure in arc chamber 99 will obviously maintain valve disc 92 seated on groove 99, thereby closing oil' vent passages 99. In the event the current interrupted is of a relatively high value on theorder of short-circuit currents, the pressure within the arc chamber may become dangerously high, andA in this event, the pressure will be high enough to move the valve-disc 94 downwardly against the bias of coil spring 99 to vent the lower end of the arc chamber to the casing 2. At the same time, referring to Fig. 3, it will be noted thatwhen the moving contact 99 has 0btained its fully separated position with respect to the xed contact bushing 92. the vent apertures |99 will be positioned above vclosure disc 94 so that the upper end of the arc chamber may then vent through the moving contact rod into the metallic tubular member 99 and thence to casing 2. The arc formed upon separation of the contacts will have been extinguished by the time the movable contact reached the position shown in Fig. 3 and inasmuch as the upper end of the arc chamber is then vented to the casing 2, the pressure of thearc-extinguishing liquid, 79

sponse to each interrupting operation of the breaker.

Time delay means for reclosing the movable Acontact 99, and lockout means for maintaining the movable contact 99 in anupper or open position in response to a predetermined number of ,closely successive interrupting operations of the breaker, will now be described. The metallic tube 99 is provided with a smooth intermediate cylindrical inner wall ||9 for receiving a substantially annular dashpot piston ||2 between the tubular member 99 and the movable contact rod 99. As shown, the dashpot piston ||2 includes an elongated sleeve portion |i4 and an enlarged upper head portion providing a shoulder ||9 between the head and sleeve portions, which is adapted to engage an annular cylinder head ||9 threadedly engaged in tubular member 99. and' provided with an aperture |22 for receiving the vsleeve portion of the dash pot piston. A coil and head ||9 in the lowermost position of they piston, without going sold.

'I'he aperture |22 through the lower cylinder head III, is preferably made to provide a slight clearance between the cylinder head and the sleeve portion ||4 of the dashpot piston, which is suillcient to permit the escape of arc-extinguishing liquid trapped between the piston 2 and the cylindrical wall ||9 of the tubular portion 99. This clearance should be designed to permit movement of the dashpot piston only at a predetermined slow rate. As shown, the upper end of the bore through the dashpot piston ||2 is provided with a series of annular notches |24 for a purpose to be hereafter described.

'I'he upper end of movable contact rod 99 is provided with a slots |29 so that a pawl lever |99 may be pivotally supported on a pivot pin |29 for movement on said pin through the slots |29 in the movable contact rod. A coil spring |92 is provided about the pivot pin |29 and has its ends engaged with the pawl lever |99 and movable contact rod 99, re-

spectively, so as to continually exert a bias on housing is provided with an enlarged chamber portion |99 intermediate a pair of spaced apertures therein for slidably guiding the movable contact rod 99, and for a purpose hereinafter to be described. i

pair of diametrically opposite 'l Theupper end oi movable contact rod 66 is pivotally connected as by pivot pin |46, with one end of an insulating link |42. The link |42 may be 'of any desired insulating material, such for y example, as ber or a syntheticresin. The opposite end of link' |42 is pivotally connected by a pivot pin |44 with an operating lever |46, which in turn is provided with a square aperture mounted on a shaft |48 whichis square in cross-section so as to be drivingly connected therewith. The

-operating shaft |48 has reduced opposite ends is supported a pair of coil springs |56, corresponding ends of which, |56 and |66,` are engaged, respectively, with a portion of cover 32 and operating lever |46. The coil springs |56 thereby operate to continually bias operating lever |46 in a clockwise direction, and therefore, to bias movable contact rod 96 into engagement with the xed contact bushing 82. It will be noted that the aperture through which shaft |48 extends is large enough to permit the shaft to be inserted therethrough, and that sleeve |54 in cooperation with a nut |55 prevents withdrawal of the shaft.

In the operation of the time delay contact closing means and lockout means ydescribed above; when the movable contact 96 is moved upwardly to interrupt the circuit through the breaker by forming an arc within insulating'tube 64, which creates pressure to move the contact upwardly, as previously described, such movement of contact rod 96 operates to stress coil springs |56. When the contact 96 attains its uppermost position, as shown in Fig. 3, the pawl lever |30 has its upper end positioned in the enlarged chamber |38 formed in the upper end cap i6 of tubular housing 62, so that it may move in a clockwise direction about its. pivot |28 under the inuence of coil spring |32 sufficiently, so that the point |36 thereof will be urged into the lower notch |24 of dashpot piston |2. Thus when the arc has been extinguished within arc chamber 63, the movable contact 96 is free to move downwardly under the iniluence of coil springs |56. This downward movement with pawl lever |36 engaged with the lower notch |24 on the dashpot piston, causes the dashpot piston to be carried down with the movable contact rod a predetermined 'distance until engagement of the upper end of pawl lever |30 with the lower aperture |3| in upper end cap causes the pawl lever to be rotated in a counter-clockwise direction about 'its pivot to remove the point |36 thereof from the lower notch |24 on the dashpot piston ||2. The resistance of the ,dashpot piston to movement is thereby removed -from the contact rod 96, andthe coil springs |56 can then move contact rod 96 into full engagement with the fixed contact bushing 82 with an 'accelerated movement or snap action. If the fault which caused opening of the breaker has been cleared when the breaker recloses, the dashpot piston ||2 moves slowly up to its normal position shown in Figs. 1 and 3 of the drawings, under the bias exerted by coil spring |26. However. if the overload is still present in the circuit be tripped substantially instantaneously to reopen the contacts in the manner previously described, and the movable contact rod will move upwardly until the arc is extinguished in the arc chamber, and will then be moved back downwardly in the same manner described above. This time, however, the point |36 of pawl lever |36 will engage in the second notch |24 of dashpot piston ||2, because on a closely succeeding interrupting operation of the circuit breaker, the dashpot piston |i2 will not have had time to reach its normal upper position shown in the drawings, but will be somewhat below this position, so that the pawl lever can engage the next succeeding higher notch on the dashpot piston. The contact rod 66 will thereupon move downwardly to engage the fixed contact bushing 82 and the dashpot piston I2 will be moved a greater distance downwardly along the cylindrical inner wall ||6 in tubular member 66.

Upon this reclosure, if the fault still has Inot been cleared from the circuit, the contact rod 96 will again be moved upwardly substantially instantaneously and will again be reclosed as before, only this time the point |36 of pawl lever |36 will engage the upper notch |24 on dashpot piston ||2, and upon reclosing the contacts, the dashpot piston will be moved a still further distance downwardly in tubular member 66. If the fault continues on the circuit after this third reclosure, the contacts will again be opened, and

' this time the point |36 of pawl lever |3|) will engage the top of dashpot piston I2 and move the shoulder IIB of the piston into engagement with the cylinder head ||8 before the pawl lever engages the edge of aperture |3| to move it in a counter-clockwise direction out of engagement with dashpot piston ||2. This will obviously prevent reclosure of movable contact rod 96 and xed contact bushing 82.

It can, therefore, be seen that upon the occurrence of a continuing fault in a circuit, our

' circuit breaker operates to automatically reclose when the contacts are reclosed, the breaker will the circuit a predetermined number of times (three times in the embodiment illustrated) and then operates to lock the contacts in open circuit position. However, if thecircuit is cleared afterthe first, second or third reclosure, the dashpot piston ||2 is permitted to assume its normal position shown in-Figs. 1 to 3, so that the breakermay operate upon the occurrence of a continuing fault at a later time, with vthe same predetermined number of reclosures prior to Alocking the contacts in an open position.

In the upper part of casing 2, we have provided novel tripping means responsive to currents passing through the breaker above a predetermined value for opening the breaker contacts suiciently to drawn an arc in the arcing chamber, so that the pressure developed by the arc may be utilized to completely and further separate the breaker contacts as heretofore described. This tripping means includes a hook-shaped trip lever |62 which is pivotally mounted adjacent the end of the hook on e. pivot pin |64, mounted on the supporting plates 56 for tubular housing 62. A coil spring |66 is provided about the pivot pin |64 and has one end |68 thereof engaged with an extension |10 of the tip of said hook-shaped trip lever |62, and the other end thereof is engaged with the top of end cap 'ID so as to continuously bias trip lever |62 for movement in a counter-clockwise direction about its pivot pin positioned with respect ing the upper end of movable contact rod 66 with link |62, is positioned to overlie the bight portion of lever |62 and lever |62 extends through the slots |26 of contact rod 96' movement of trip lever |62 under the influence of .spring |66, will operate to engage pivot pin |66 and raise contact vrod 66 a slight distance away from ilxed contact bushing 62 until the extension |16 of trip lever |62 engages the side of end cap 16. Further movement of contact rod 66 in an upward direction by the pressure developed in the arc in the arc chamber is free of trip lever |62.

The upper end of trip lever |62 has secured thereto a catch portion |12 secured to the trip lever between insulating plates |16, as for example, by a -rlvet |16. The upper projecting end of catch |12 is curved laterally so as to present an edge portion for engagement with a latching means. A bimetallic strip |16 4has one end thereof secured to flange 66 of the cover 62, and the other end thereof extends across the top of casing 2 and is provided with an adjustable latch member |62, which is being threadedly engaged through the free end of the bimetal strip |16. 'I'he bimetal strip is secured to flange 66 in any desired manner, such Afor example, as by screws |66, and the strip may be constructed in a manner well known in the art, of a pair ,of laminations comprising materials having different coemcients of expansion rigidly secured together, with, in the present instance, the upper lamination being of a material such as steel, having a relatively low coeiilcient of expansion, and the lower lamination being of a material such as brass, having a relatively high coetiicient of expansion, so that when the bimet-al strip is heated, the outer end thereof will deflect upwardly to bring the latch portion |62 thereof up out of the path of movement of catch |12 on trip lever |62 when moved by coil spring |66.

A flexible shunt |66 electrically connects the outer end .of bimetal strip |16 with the `upper end of movable contact rodv 96, and movable contact rod 96 is provided with a splasher member |66 secured to the upper end thereof in any.

desired manner, such for example, as by welding or the like. As shown, the splasher member |66 extendsv generally outwardly and upwardly from the movable contact rod below bimetal strip |16, so as to throw oil onto the bimetal strip when the contact rod moves upwardly to interrupt the circuit, and thereby to aid in cooling the strip to hasten its return back to its normal position shown in Figs. 1, 2 and 3.

IOrl top of casing cover 62 and at one side thereof, we provide an angle piece |66, one leg of which is secured to the flange 66 of the cover 62 as by screws |96, and the other legl of which' so as to be centrally thereto. Obviously,

adjustable by virtue of value passed therethrough to deflect in an upward direction. y

Upon the occurrence of an overloadin the circuit', bimetal strip |16 'will be deflected upwadly, which will remove the latch portion |62 thereof-from the path of movement of catch |17. on trip lever |62, allowing this lever to rotate in a counter-clockwise direction d ue to the inuence of coil spring |66. This rotation of trip lever |62 lifts the movable contact rod 66 by engagement of pivot pin |66 a slight amount suilicient to establish an arc between the movable contact rod and the fixed contact bushing 62. 'I'his lift need not be very great, and in practice, it has been found that a separation of approximately 1A" is satisfactory. This separation of the circuit breaker contacts causes pressure to be built up in the arc chamber as previously described, and causes further separation has secured thereto a conductorsocket |92 pro- 4 vided with a clamping screw |96 for clamping a conductor within the socket. y

'Ihe electrical circuit through our circuit breaker may now be traced from conductor socket |92 on cover 62, through cover 32, bimetal strip |16, flexible shunt |66, movablecontact rodv 66, fixed contact bushing 62, lower end cap 6 6, conducting spring 16, bolt I6 of the lower terminal assembly, and terminal strip 26 to terminal sockets 26. It can thereby be seen that the bimetal strip |16 is connected in series in the circuit so as to be responsive to currents above a predetermined of movable contact 96 from fixed contact bushing 62 in an upward direction. In driving upwardly, pivot pin |66 will engage the curved edge |63 of trip lever |62 to reset the trip lever in its normal position shown in Fig, 1. The curved surface |66 of the trip lever acts as a cam surfacevto move the trip lever in a clockwise direction from its tripped position to a position where the catch |12 thereof may be reengaged by latch |62 on the bimetal strip. It will be noted that the upper end of the trip lever '|62 is formed with a substantially straight edge |66 of considerable extent so that when the movable contact rod 96 is in its upperposition, shown in Fig 3, it will maintain the trip lever |62 in the position where its catch |12 may be re-engaged by latch |62 for a considerable travel of contact rod 96 adjacent its fully open POSI- tion. In other words, the trip lever |62 is maintained in a-resetting position for a predetermined ,time (the time required for pivot pin |66 to travel along the straight edge |65 of the trip lever). before the circuit breaker contacts are reclosed. Cooling of the bimetallic strip |16 vto its normal position is hastened, of course, by the splashing of liquid from container 2 thereover, by splasher member |66 when the movable contact rod 66 moves upwardly to open the circuit. When the trip lever |62 is reset in the position shown in Figs. l, 2 and 3, the contact rod 96 then moves downwardly, following, of course, venting and flushing of the arc chamber, as previously described, and carrying with it for a predetermined distance, dashpot piston H2, all as above described. If the overload is still present in the circuit, bimetal strip |16 will again deflect in the same manner as it did the rst time to again cause trip lever |62 to separate the breaker contacts and permit the movable contact 96 to open the circuit and tinueuntil the overload .either clears, or after a predetermined number of reclosures, the movable contact 96 is locked by the dashpot piston ||2 in an open circuit position.

We prefer to provide an outer cover |96 over the hollow portion of cover 62, to normally conceal the operating handle |52 and protect it from the `elements when the breaker is mounted in an exposed location. The cover |66 is inverted over the hollow portion of cover 92 and is provided with top and side and end walls, and is pivoted at one corner thereof on a pivot pin |96 to the cover 62. Obviously, when it is desired to refill the breaker. or when access is desired to the operating mechanism, outer cover |96 may be pivotally moved in a clockwise direction, as

reclose as before. This will cone ing handle extension |52 will be positioned in oute'rcover igt and will not be visible from the exterior of the breaker (Fig. l). the breaker is in an open position, especially when the contacts thereof have been locked open by the lockout means previously described, extension i552 of the operating handle will be at least partially positionedbelow outer cover as is apparent from'Fig. 3. This will provide a readily visible indication as to whether or not the circuit breaker is locked open, so that if it is desired to reinsert the breaker in the circuit, it is merely necessary to engage the extension E52 of the operating handle with a hook stick or the like, and pull downwardly thereon to slightly raise movable contact 96. This will release pawl lever i3d from notches l2d on the dashpot piston H2 and permit the piston to move upwardly, and as soon as th piston hasmoved upwardly a distance corresponding to the distance between adjacent notches i225, the operating handle may be released and the circuit breaker contacts will be closed by springs |56 in a manner described above.

Referring to Figs. 4 and 5, it will be apparent that the hollow portion of casing cap 32 is provided on one side thereof adjacentone' end. with a reentrant portion 282 having a top wall 265 overhanging this reentrant portion. This is for the purpose of mounting between the top of cover 32 and overhanging wall 204 a tubu However, When l l includes means to separate the breaker contacts sufdciently to draw an arc therebetween so that pressure developed by the arc in a substantially i closed arc chamber operates to fully separate said lar sight glass 20E, within which is adapted tc move the upper end of a float rod 208, which has connected to Athe'lower end thereof, a float 2li! for indicating the level of arc-extinguishing liquid within casing 2.

Also mounted on the same side of the hollow portion of casing cover 32, we provide a manually operable lock lever 2l2 for locking the circuit breaker contacts in an open position. As shown, this lever 2I2 is freely pivoted on a pivot pin 2M mounted on cap 32 so as to be movable into engagement with a shoulder 2|3 provided on operating lever |50 when the lever is in its lowermost position corresponding to the upper position of movable contact rod`96, and, therefore, the open position of the circuit breaker contacts. This lever may be manually moved away from shoulder 2l3 on operating lever |50, and is normally adapted to be positioned resting en integral supporting'V means 2I6 extending laterally outwardly from the adjacent side of the hollow portion of cap 32. Such a manually operable lockout means is desirable in the event it is desired to work on the circuit protected by our interrupter and insure an open circuit for safety purposes.

From the foregoing it should be appare t that we have provided a circuit breaker of t e type capable of automatically reclosing a circuit following an. interrupting operation, which is operable to reclose the circuit a predetermined number of times and lock the breaker contacts open upon the occurrence of a permanent fault, and which will never lock the circuit breaker ,con-V tacts open irrespective of the number of time spaced interruptions. Our novel breaker is also characterized by a novel arrangement of parts contacts. Closing of the circuit breaker contacts is opposed by the novel time delay means disclosed, which is also responsive to al predetermined number of closely successive reclosures for locking the circuit breaker contacts in an open position. We have also disclosed certain specific features relating to a circuit breaker housing, and although all of these features have been particularly disclosed in a single unitary apparatus, it will be obvious to those skilled in the art that many ofthese features may be used independently, or inconjunction with other types of circuit breakers.

Having described preferred embodiments of our invention in accordance with the patent statutes, we desire that it be understood that our invention is not limited to the particular embodiments dis closed, since it will be obvious, particularly to persons skilled in the art, that many changes and modiiications may be made in these specic structures without departing from. the broad spirit and scope of our invention. Therefore, we desire 'that our invention be interpreted as broadly as possible and that it be limited only'by what is expressly stated in the following claims and by the prior art.v

We claim as our invention:

1'. In a circuit interrupter, separable contacts mounted in a normally closed arc chamber with one of said contacts slidably mounted in a wall of said chamber for movement into and out or engagement with respect to the other of said contacts, normally closed vent means for said chamspouse to movement of said movable contact to substantially its fully opened position, and a.

check valve controlling a chamber inlet for .permitting fluid ilow into said chamber in response to a reduction in pressure therein.

2. In a circuit interruptor, separable contacts mounted in a normally closed arc chamber with one of said contacts slidably mounted in a wall of said chamber for movement into and out of engagement with respect to the other of said contacts, said one contact having a vent passage therethrough, the outer end of which is located so as to be positioned outside of said chamber only when said movable contact is separated a predetermined distance from the other of said contacts, and inlet means for Vsaid chamber normally closed at least during a circuit interrupting operation and adapted to open at least following Y a circuit interrupting operation to permit flushing of said chamber.

3. A circuit breaker including a container adapted to be substantially lled with an arcextinguishing fluid, a substantially closed arc chamber therein, separable contacts in said chamber, vent means for an upper portion of said chamber adapted to be opened in -response to a predetermined separation of said contacts, and a lower opening for said chamber controlled by a check valve for permitting duid now solely inwardly with respect to said chamber.

and simpliied` structure, so that a breaker of reduced size and which is economical-in construction, is provided. Speciiically, we have disclosed 4. In a circuit breaker, a movable contact rod, tubular means having a cylinder portion about said rod, piston means movably mounted in said cylinder means, and a pawl and ratchet connec tion ybetween said rod and pistonmeans operative to connect said rod and piston means for movement together upon movement of said rod in a l said means being mounted for relative movement,

and means connecting said rod and one of said ilrst two-mentioned means for movement with said rod close the electrical circuit through said breaker. 6. In a circuit breaker, a movable contact rod, tubular means having a cylinder portion about said rod, piston means movably mounted in said cylinder means,`and a pawl and ratchet connection between said rod and piston means operative to connect said rod and piston means for movement together upon movement of said rod in a direction to close the circuit through said breaker, and means normally biasing said piston means for movement in the opposite direction.

7. In a circuit breaker, a movable contact rod, tubular'means having a cylinderv portion about said rod, piston means in said cylinder portion, said means being mounted for relative movement, pawl and ratchet means connecting sa/id rod and one of said rst two-mentioned means for movement with said rod when said rod moves in a directionto close the electrical circuit through said breaker, and stop means for said one means positioned beyond the path of movement of said one means with said rod on the first closing movement thereof in any series of closely successive reclosures, whereby to maintain said rod in open circuit position-in response to a predetermined number of closely successive circuit closing operations thereof.

8. In a circuit breaker, a movable contact rod, tubular means having a cylinder portion about said rod, piston means movably mounted in said cylinder means, a pawl and ratchet connection between said rod and piston means operative to connect said rod and piston means for movement together upon movement of said rod in a direction to close the circuit through saidl breaker, means normally biasing said piston means for movement in the opposite direction, and stop means for said piston means positioned to be engaged thereby to maintain said contact rod in open circuit position in response to a predetermined number of closely successive circuit closing operations thereof.

9. In a circuit breaker, a movable contact rod tubular means having-a cylinder portion about said rod, piston means in said. cylinder portion said means being mounted for relative movement, means connecting s'aid rod and one of said nrst two-mentioned means for movement with said rod when said rod moves in a direction to close the electrical circuit through said breaker,

when saidy rod moves in a direction to 7 1i. In a circuit breaker, a movable contact rod. tubular means having a cylinder portion about said rod, piston means movably vmounted in said cylinder means, a pawl and ratchet connection between said rod and piston means operative to connect said rod and piston means for movement together upon movement of said rod in a. direction toclose the circuit through said breaker, said contact rod being hollow and 'having a slotted wall portion for mounting an element of said pawl and ratchet connection therein, said tubular means including an arc chamber portion adjacent said cylinder portion and into which said contact rod extends, contact means in said chamber for cooperation with said contact rod to control the electric circuit through said breaker, vent passage means through the wall of said hollow contact rod and positioned to be located outside said arc chamber only after predetermined separation of said contact rod and contact means, and partition means in said hollow contact rod between said slotted portion and said vent passage means.

12. In a circuit interrupter, a container adapted to be substantially lled with an arc- 'extinguishing liquid, tubular means in said container including an arc chamber portion having separable contacts therein, and a portion housing fluid time delay means operable to retard closing movement of' said contacts, means flushing said arc chamber portion in response to separation oi' said contacts to interrupt the circult, and said time delay means having intake means below the level of said liquid whereby to` positively insure flushing of said chamber por.- tion irrespective of the viscosity ot said liquid."

13. In a circuit breaker unit, tubular supporting means including an arc chamber portion, and an adjacenthousing portion, closure means for said arc chamber portion including a ilxed partition'between said housing and chamber portions, separable contacts in said chamber portion, andtime delay means in said housing portion for delaying closure of said contacts a predetermined time after an interrupting operation thereof.

14. In a circuit breaker unit, tubular supporting means including a substantially closed arc chamber portion, and an adjacent housing portion, separable contacts in said chamber portion, and time delay means in said-housing portion for delaying closure of said contacts a pre- Y determined time after an interrupting operation said tubular means including an arc chamber Y portion adjacent said cylinder portion and into which said contact rod extends. and contact means ln said chamber for cooperation with said contact rod to control the electric circuit through said breaker.

. 10. In a circuit breaker, a movable contact rod.'

tubular means having a cylinder portion about said rod, piston means movably mounted in said cylinder means, and a pawl and ratchet connection between said rod and piston vmeans operative to connect said rod ard piston means fer movement together upon movement of said rod in a direction to close the circuit through said breaker, said contact rod having a slotted portion for mounting one element of said pawl and ratchet connection.

thereof, supporting means etxending from said tubular means for at least partly supporting electro-responsive means to separate said contacts suillciently to draw an arc therebetween, at

least one of said lcontacts being movable and having a part extending-through a wall of said chamber whereby the pressure generated by said arc will further separate said contacts, and means normally biasing said contacts into engagement to automatically close said contacts when said arc is extinguished.

.15. In a circuit breaker unit, tubular st xpporting means including a substantially clod arc chamber portion, and an adjacent housing portion, separable contacts in said chamber portion, time delay means in said housing portion for delaying closure oi' saidcontacts a predetermined time after-an internmting operation thereof, supporting meam extending'fmm said tubularmeans for at least partly supporting electro-responsive means to separate said contacts sumcient to draw an arc therebetween,

operable current responsive means normally maintaining said member against movement.

said electro-responsive means including an actuating member movably mounted on said supporting means and biased for movement in a. direction to separate said contacts, and an element normally opposing said movement of said actuating member, but movable in response to predetermined electrical conditions of the circuit to release said actuating member.

16. In a circuit breaker, an interrupter unit comprising tubular supporting means including a substantially closed arc chamber portion, and an adjacent housing portion, separable contacts in said chamber portion, time delay means in said housing portion for delaying closure of said contacts a predetermined time after an intercomprising tubular supporting means including a substantially closed arc chamber portion,v and an' adjacent housing portion, separable-contacts in said chamber portion, time delay means in said housing portion for delaying closure of said contacts a predetermined time after an interrupting operation thereof, supporting means extending from said tubular means for at least partly supporting electro-responsive means to separate said contacts, an insulating container for said unit, a cover for said container and to which said. supporting meanss connectedto operatively support said unit in said container from said cover, and an operating member movably mounted on said cover and connected to at least one of said contacts and having an operating portion extending to the outer side of said cover.

i8. In a circuit breaker, a substantially closed arc chamber, separable contacts therein, one of which extends through a wall of said chamber and the other being substantially fixed in said chamber, means mounting said chamber and said one contact for relative movement, an actuating member biased for movement in one direction to separate said contacts suiliciently to draw an arc therebetween, said member having a lost motion connection to one of said contacts Y whereby the arc pressure in said chamber is to further separate said contacts, and

19. In a circuit breaker, a substantially closed arc chamber, separable contacts therein, one of which movably extends through a wall of said chamber and the other being substantially xed in said `chamber, an actuating lever biased for movement in one direction to separate said contacts sufciently to draw an arc therebetween,` said lever having a portion adapted to contact.

an operating part operatively secured to said one contact to move the same out of engagement with the other of said contacts whereby said one contact is free to move further to increase the gap lbetween said contacts by the pressure developed by said arc, and current responsive means normally preventing movement of said lever in said one direction.

20. In a circuit breaker, a substantially closed arc chamber, separable contacts therein, one oi which movably extends through a wall of said chamber and the other Ibeing substantially fixed xin said chamber, an actuating lever biased for movement in one direction to separate said con` tacts sufficiently to draw an are therebetween, saidlever having a portion adapted to contact an operating part operatively securedto said one contact to move the same out of engagement with the other of said contacts whereby said one contact is free to move further to increase the gap between said contacts by the pressure developed by said arc, and current responsive means nor- ,mally preventing movement of said lever in said one direction, said lever including a cam portion adapted to be engaged by said operating part upon said further movement of said one contact to reset said lever in a position to be reengeged by said current responsive means.

2l. In a circuit breaker, a substantially closed arc chamber, separable contacts therein, one of which movably extends through a wall of said chamber and the other being 'substantially fixed in said chamber, an actuating lever biased for movement in one direction to separate said contacts suiciently to draw an arc therebetween, said lever having a portion adapted to contact an operating part operatively secured to said one contact to move the same out of engagement with the other of said contacts whereby said one contact is free to move further to increase the gap between said contacts by the pressure developed by said arc, current responsive means normally preventing movement of said lever in `said one direction, said lever including an inner cam portion adapted to be engaged by said operating part upon said further movement of said one contact to reset said lever in a position to be reengeged by said current responsive means, and an outer substantially straight portion on said lever engageable by said operating part adjacent the end of its opening movement to maintain said 'lever in a position to be reengaged by said current responsive means a predetermined time,

22. In a circuit interrupter, a container adapted to be substantially filled with an arc-extinguishing liquid, interrupting means in said container and including separable contacts submerged in said liquid, means for moving one of said contacts out of engagement with the other of said contacts, bimetal latch means controlling said contact moving means in response to predetermined current conditions, and normally positioned above the level of the liquid in said container, and means responsive to aninterrupting operation of said interrupter for subjectingsaid bimetal means to said liquid to shorten the normal cooling time thereof.

23. In a circuit interrupter, a container adapted to vbe substantially lled with an arc-extinguishing liquid, interrupting' means in said container and including separable contacts submerged in said liquid, means for movingone of said contacts out of engagement with the other of said contacts, thermal latch means controlling said contact moving means in response to predetermined current conditions, and normally positioned above the level of the liquid in said container, and means responsive to an interrupting operation of said interrupter for subjecting said thermal means to saidv liquid to shorten the normal cooling time thereof..

24. In a circuit interrupter, separable contacts mounted in:V a, normally closed arc chamber adapted to be lled with an arc-extinguishing iluid, means 'for moving said contacts into and i out of engagement, normally closed vent means :,siaaai for said chamber adapted to open in response to predetermined separation of-said contacts, an inlet opening for said chamber, and check valve means controlling said inlet opening to permit fresh iluid to flow into said chamber to .replace used uid which escapes from said vent.

25. lIn a circuit interrupter, xed and movable contact means, means biasing said movable contact means into engagement with said tlxed contact means, electroresponsive means for causring separation of said movable contact means from said fixed contact means a distance at least sumcient to draw an arc, and means utilizing the pressure developed by said arc to increase the separation of said contacts and extinguish the arc, whereby vsaid contact means are automatically reclosed by said biasing means.

26. In a circuit interrupter, xed and -movable contact means, means biasing said movable contact means into engagement with said fixed contact means, time delay means opposing movement oi said movable contact means by said biasing means, electroresponsive means for causing separation of said movable contact means from said flxed contact means a distance at least sutilcient to draw an arc, and means utilizing the pressure developed by said arc to increase the separation of said contacts and extinguish the arc, whereby said contact means are automatically reclosed by said biasing means a predetermined time after a circuit-interrupting operation.

27. In a circuit interrupter, fixed and movable contact means, means biasing said movable contact means into engagement with said fixed contact means, time delay means opposing movement of said movable contact means by said biasing means, electroresponsive means for causing separation of said movable contact means from said xed contact means a distance at least sufilcient to draw an arc, means utilizing the pressure developed by said arc to increase the separation of said contacts and extinguish the arc, whereby said contact means are automatically reclosed by said biasing means a predetermined time after a circuit-interrupting operation, and means associated with said time delay means for preventing movement of said movable contact means into engagement with said fixed contact means in response to a predetermined number of successive reclosures thereof.

28. In a circuit interrupter, an arc chamber which is closed at least during a circuit-interrupting operation, separable contacts mounted in said chamber in a manner to be urged apart by any pressure devel :ping in said chamber, electroresponsive means for separating said contacts and having a lost-motion connection therewith whereby the pressure generated by said arc in Isaid chamber will be eiective to further separate said contacts independent of said electroresponsive means.

29. In a circuit interrupter, an arc chamber which is closed at least during a circuit-inter- -rupting operation, separable contacts in said chamber is operable to cause further movement of said movable contact away from said other contact independent of said electroresponsive means. i

30. In a circuit interrupter, an arc chamber which is closed at least during a circuit-interrupting operation, separable contacts mounted in said chamber in a manner to be urged apart by any pressure developing in said chamber, electroresponsive means for separating said contacts and having a lost-motion connection therewith whereby the pressure generated by said arc in said chamber will be effective to further separate said contacts independentof said electroresponsive means, and means biasing said contacts into engagement whereby the circuit will be automatically reclosed in response to extinction of said arc.

31. In a circuit interrupter, an arc chamber which is closed at least during a circuit-interrupting operation, separable contacts mounted in said chamber in a n'ianner to be urged apart by any pressure developing in said chamber, electroresponsive means for separatinggsaid contacts and having a lost-motion connection therewith whereby the pressure generated by said arc in said chamber will be effective to further separate said contacts independent of said electroresponsive means, means biasing said contacts into engagement whereby the circuit will be automatically reclosed'in response to extinction of said arc, and time delay means eilective to delay reclosure of said contacts under the influence of said biasing means.

32. In a circuit breaker, a substantially closed arc chamber, separable contacts therein, one of which movably extends through a wall of said chamber and the other being substantially ilxed in said chamber, an actuating lever biased for movement in one direction to separate said contacts sufllciently to draw an arc therebetween, said lever having a lost-motion connection with said one contact to move the same out of engagement with the other of said contacts whereby said one'contact is free to move further to increase the gap between said contacts by the pressure developed by said arc, and currentresponsive means normally preventing movement of said lever in said one direction.

33. In a circuit breaker, a substantially closed arc chamber, separable contacts therein, one of which movahly extends through a wall of said chamber and the other being substantially ixed in said chamber, an actuating member biased for movement in one direction to separate said contacts sumciently to dr'aw an arc therebetween, said member having a lost-motion connection with said one contact to move the same out o! engagement with the other of said oontactswhereby said one contact is free to move further to increase the up between said contnctsbythepressuredevelopedbysaidarc,

and current-responsive means normally preventimmovementofsaidmemberinsaidonedirection.

34.Inadrcuitbreaker,asubstannllyclosed arcchamber,separableoontactsthm'ein.oot whichmovablyextemhtluuhawallotsaid chamberandtbeotherbdngmhstantiallyilxed insaidclnmber.anactllatingleverlhaedfor movementmonedirectinntoamaratenidcontactssumciently todrawanarc, said lever havingalost-motinnoonnectionwith saidonecontacttomovethesameoutotmgamaitwithtbeotherofsaidoitactsvhereby said one contact is tree to rmove further to increase the gap between said contacts by the pressure developed by said arc, and current-responsive means normally preventing movement of said lever in said one direction, said lever including a cam portion adapted to be engaged by said operating part upon said further movement off said one contact to reset said lever in a position to be reengaged by said current-responsive means. Y o

35. Ina circuit interrupter, separable contacts, electroresponsive means for separating said contacts to draw an arc andhaving a lost-motion connection therewith, and means responsive to said arc for further separating said contacts independent of said electroresponsive means to insure sufllcient contact separation to extinguish the arc.

36. In a circuit interrupter, a casing, interruptin-g means in said casing including separable contacts biased into engagement, electroresponsive means for separating said contacts, and means responsive to a predetermined number of successive circuit-interrupting operations for maintaining said contacts separated; a cover for said casing, an operating member movably mounted on the outside of said cover and associated with said contacts so as to assume diierent positions at least when said contacts are in engagement and maintained separated, respectively, means on said cover for receiving and concealing said operating member in its position corresponding to the engaged position of said contacts, and said member in its other .position projecting from said means so as to provide a readily visible indication of the maintained' open position of said contacts.

37, In' a circuit interrupter, a casing', interrupting means in said casing including separable contacts biased into engagement, electroresponsive means for separating said contacts,

' and means responsive to apredetermined number of successive circuit-interrupting operations Y for maintaining said contacts separated; a cover for said casing, an operating member movably mounted on the outside of said cover and asso-4 ciated with said contacts so as to assume different positions at least when said contacts are in engagement and maintained separated, respectively, sleet hood means pivotally mounted on said cover for receiving and concealing said operating member in its position corresponding to the engaged position of s aid contacts, and

l said member in its other position projecting from said hood means so as to provide a readily visible indication of the maintained open position of said contacts.

38. In a circuit interrupter, a casing, interrupting means in said casing including separable contacts biased into engagement, electroresponsive means for separating said contacts, and means responsive to a predetermined number of successive circuit-interrupting operations for maintaining said contacts separated; a cover for saidv casing, an operating member movably mounted on the outside of said cover and associated with said contacts so as to assume raised and depressed positions at least whensaid contacts are in engagement and maintained separated, respectively, and releasable 'locking means on said cover for releasably maintaining said operating member in its depressed position correspending to said maintained separated position of said contacts.

3i?. In a circuit interrupter, a casing, interrupting means in said casing including separable contacts biased into engagement, electroresponsive means for separating said contacts, and means responsive to a predetermined number of succesive circuit-interrupting operations for maintaining said contacts separated; a cover for said casing, an operating member movably mounted on the outside of said cover and associated with said contacts so as,to assume'diiierent positions at least when said contacts are in engagement and maintained separated, respectively, means on said cover for receiving and concealing said operating member in its position corresponding to the engaged position of said contacts, and said member in its other position projecting from said means so as to provide a readily visible indication of the maintained open position of said contacts, and releasable locking means on said cover for releasably maintaining said operating member in its projecting position.

40. In a circuit interrupter, separable contacts mounted in a normally closed a/rc' chamber with one of said contacts slidably mounted in a wall of said chamber for movement into and out o f en gagement with respect to the other of said contacts, normally closed vent means for said chamber, said vent means adapted to be opened in response to each circuit interrupting operation of said contacts, and a check valve controlling a chamber inlet for permitting uid i'low into said chamber in response' to a reduction in pressure therein. i

41. A circuit breaker including a container adapted to be substantially filled with an arcextinguishing liquid, a substantially closed arc chamber therein, separable contacts in said chamber, vent means for an upper portion of said chamber adapted to be opened in response to each circuit interrupting operation of said contacts, and a lower opening for said chamber controlled by a check valve for permitting liquid flow solely inwardly with respect to said chamber.

42. In a circuit interrupter, separable contacts mounted in a normally closed arc chamber adapted to be lled with an arc-extinguishing fluid, means for moving said contacts into and out of engagement, normally closed vent means for said chamber adapted to open in response to each circuit interrupting operation of said contacts, an inlet opening for said chamber, and check valve means controlling said inlet opening to permit fresh uid to flow into said chamber to replace used iiuid which escapes from said vent.

43. In a circuit interrupter, separable contacts mounted in a normally closed arc chamber with one of said contacts slidably mounted in a wall of said chamberfor movement into and out of engagement with `respect to the other of said contacts, means for separating said contacts to interrupt the circuit, means for automatically reclosing said contacts in response to a circuit interrupting operation, normally closed vent means for said chamber, said vent means adapted to be opened in response to each circuit interrupting operation thereof, a check valve controlling a chamber inlet for permitting iuid iiow into said chamber in response to a reduction in pressure therein, and time delay means for retarding clOsing of said contacts to pennit ilushing of said chamber by ow of fresh iiuid in said chamber inlet for replacement of contaminated y fluid escaping from said vent means.

' said rod, piston means movably molmted in said cylinder means, and means connecting said rod and piston means for movement together during at least. part of the movement of said rod in one direction.

45. In a circuit breaker, a movable contact rod, tubular means having a cylinder portion about said rod, annular piston means movably mounted in said cylinder means, and slidable between said rod and cylinder portion; and means connecting` said rod and piston for movement together during at least part of the'movement of the said rod in one direction.

46. In a circuit breaker, a container for an arc extinguishingl liquid, a movable contact rod in said container, tubular means having a dashypot cylinder portion about said rod below the liquidl level in said container, dashpot piston means in said cylinder portion, said means being 47. In a circuit interrupter, a container vadapted to be substantially nlled with an arcextinguishing liquid, interrupting means in said container and including separable contacts submerged in said liquid, means for moving said contacts apart to interrupt the circuit, bimetal latch means controlling said contact moving means in response to predetermined current conditions, and normally positioned above the level IV4 having an open end, a terminal cap for said end, a line terminal at the opposite end 'of said container having aportion extending through the container wall to the interior thereof, an interrupting assembly mounted on said cap including separable contacts, electro-responsive 'contact separating means and reclosing means for the contacts, so that al1-oi said elements are Y removable from said container as a unit with said cap, said contacts and electro-responsive means .connected in series between said cap and a projecting assembly terminal positioned to be adjacent said line terminal when said cap is secured in operative position with respect to said container, and resilient conducting means telescopically engaging a portion o! said assembly terminal and stressed against said line terminal in said operative position of the parts relative to the container. v

49. In a circuit interrupter, a uid container having an open end, a terminal cap for said enel, a line terminal at the opposite end of said container having a portion extending through the container wall to the interior thereof, an interrupting assembly mounted on. 'said cap including separable contacts, electro-responsive contact separating means and reclosing means for the contacts, so that all of said elements are removable from said container as junit with said cap,

said contacts and electro-responsive means connected in series between said cap and a projecting assembly terminal positioned' to be adjacent said line terminal when said cap is secured in operative position with. respect to said container, a coil conducting' spring telescopically engaging a portionof said assembly terminal and stressed against said line terminal in said operative position of the parts relative to thejcontainer.'

:mm' L. RAWLINS. JAMES M. WALLACE. 

